Stuart Lancaster is playing his World Cup trump cards when England face Ireland in their final warm-up match before clashing with Wales, Australia and Fiji at rugby’s showpiece event.

The stakes couldn’t be higher for those starting a match neither side can afford to come unstuck in because it would send the loser into the tournament having suffered back-to-back defeats.

It’s clear the England team selected by coach Lancaster is close to the XV he wants to field in Pool A of the World Cup. Beat the Six Nations champions and it will probably be selected enbloc by the hosts for the opener with Pacific Nations Cup kings Fiji at Twickenham on September 18.

Come unstuck against the Irish and Wales boss Warren Gatland’s assertion the English don’t know their best side or the tactics they want to employ could ring true.

Putting the Twickenham factor to one side, how would Gatland’s probable Wales World Cup team fare against the likes of Mike Brown, Jonathan Joseph, Dan Cole, Courtney Lawes, Chris Robshaw and company in terms of ability? Rugby Correspondent Andy Howell goes through each unit and gives his view.

Back-three (Mike Brown, Jonny May, Anthony Watson)

Anthony Watson is a danger

Mike Brown was Six Nations player of the tournament in 2014 but was promptly found out during the tour of New Zealand when the All Blacks played on his weaknesses. They turned him in defence, employed a quick chase and forced him on to his right foot – he kicks with his left. Jonny May is rapid but resembles a headless chicken at times.

Leigh Halfpenny is part of Wales' back three

However, Anthony Watson on the other wing is a tremendous and dangerous prospect capable of unlocking defences with his tricky footwork. Leigh Halfpenny, although he doesn’t possess the counter-attacking zeal of Brown, is a more assured player and provides match-winning points with his goal-kicking while a firing George North takes some handling when he’s on the ball.

Verdict: Halfpenny’s presence gives Wales an advantage but North will need to tighten his defence if he’s marking Watson while it’s unclear at this stage who will be on the other wing for each country.

Centres (Brad Barritt, Jonathan Joseph)

Brad Barritt starts in the centre

I’d be mightily relieved if this is the England No.12 and 13 combination because the further Henry Slade is away from their team the better.

By all accounts, the Red Rose management was raving about union convert Sam Burgess’ contribution against France at Twickenham but their judgement must have been clouded by him coming from rugby league.

Jamie Roberts is better

Slade was the visionary playmaker and key man but they seem blind to his potential, preferring a basher like Brad Barritt. Outside-centre Jonathan Joseph is a classy runner but having Barritt inside him might nullify his threat.

Verdict: The power of go-to man Jamie Roberts and the finesse of Scott Williams outside men means Wales will have no qualms about facing this potential England combination.

Half-backs (Ben Youngs, George Ford)

England's George Ford scores a try

Lancaster has turned up the heat on outside-half George Ford by claiming Owen Farrell is pushing him all the way for the No.10 jersey.

Farrell is a superior goalklcker but lacks the attacking edge of Ford, who gave Wales problems last February, and Wales will hope they pick the former because it means England will be likely to revert to a more forward-orientated approach while lacking the power to strangle quality opponents.

Ben Youngs is a lively scrum-half who can provide telling moments but also has a tendency to drift out of games while having a tactical kicker in Richard Wigglesworth on the bench could be a further sign the English are considering reining in their more expansive approach.

Verdict: There’s not much to choose between half-back combinations with Rhys Webb and Dan Biggar flourishing for Wales last term and it could come down to who produces their A game on the day.

Front-row (Joe Marler, Tom Youngs, Dan Cole)

Dan Cole (Image: Action Images / Andrew Couldridge)

I’d be happy if David Wilson remains a fringe figure because his scrummaging power at tighthead prop would be a worry for Wales with Warren Gatland’s front-row yet to be settled with Samson Lee having to prove his fitness and it being early days for new recruit Tomas Francis. Dan Cole struggled against France’s first-choice front-row while converted hooker Tom Youngs, who used to be a centre, isn’t a stronger scrummager and Joe Marler isn’t everybody’s cup of team. An England front-row containing Wilson and Alex Corbisiero would strike more fear into Welsh hearts.

Verdict: Wales great Gethin Jenkins is a colossus in the loose while either hooker, Scott Baldwin or Ken Owens, provide oomph. Tighthead could be a problem with no guarantee Lee will be ready while it’s too early to make a judgment on Francis at top level.

Locks (Courtney Lawes, Geoff Parling)

Courtney Lawes

Joe Launchbury has plenty of admirers but the injuries he has suffered in recent campaigns appear to have slightly stunted his growing reputation in the international game.

Courtney Lawes is highly-touted by some but I’m not convinced and question his consistency. Put him up against mediocre opposition and he can be sensational but I’ve seen him be anonymous and ineffective against better opponents. But the decision of Lancaster to pick Geoff Parling does concern me.

Alun Wyn Jones should be fit for the England clash

He’s a reliable ball-winner at the lineout, is hugely experienced and possesses strong leadership traits, as he exhibited for the Lions when they conquered Australia two years ago.

Verdict: Alun Wyn Jones, if fit, would clearly walk into either team while Wales have plenty of depth at lock and would fancy their chance of winning this facet of play.

Back-row (Tom Wood, Ben Morgan, Chris Robshaw)

England captain Chris Robshaw is what’s known as a six-and-a-half – a cross between a blindside and openside flanker – occupying the speedster’s role in the back-row.

But he’s not the quickest around the park and neither is blindside Tom Wood. Both are dependable players but might struggle to impose themselves if the England front-five isn’t at it’s best.

The higher work-rate of former Scarlets ace Ben Morgan appears to be winning the race with Billy Vunipola for the No.8 jersey after recovering from a broken leg and he’s a player who can make things happen.

Verdict: Skipper Sam Warburton, or Justin Tipuric, Taulupe Faletau and Dan Lydiate would all probably start for the Red Rose if they were English. Fortunately, they’re Welsh!